Due to their high heat transfer efficiency, automotive style brazed heat exchangers have been modified for residential and commercial air conditioning and heat pump applications. A typical modified automotive heat exchanger includes a pair of manifold headers having a plurality of flat tubes in hydraulic connection therebetween for refrigerant flow from one manifold header to the other. Having uniform refrigerant distribution through the plurality of flat tubes is important for optimal heat transfer. To provide for uniform refrigerant distribution through the core of flat tubes, larger diameter manifold headers are used in conjunction with internal refrigerant distribution and collection conduits in the inlet and outlet manifold headers, respectively.
In order to meet packaging constraints for residential and commercial applications, the larger diameter manifold headers of the modified automotive heat exchanger may be bent about an axis on a mandrel. With larger diameter manifold headers, the bending process has a tendency to deform the wall of the manifold header into a substantially egg-shaped cross sectional profile.
It is desirable to have a bending support adapted for use in the bending of a manifold header of a heat exchanger, in which the bending support prevents stress concentrations from deforming the inner radius of the bend. It is further desirable to have a bending support adapted to hold and maintain the internal refrigerant conduit in a predetermined position within the manifold header during the bending process and which assists in the bending of the internal refrigerant conduit to conform to the bend contour of the manifold. It is still further desirable for a method of using the bending support in the manufacturing of a heat exchanger having a bent manifold header that includes an internal refrigerant conduit conforming to the bent contour of the manifold.